autoalarm vs auto-alarm

autoalarm and auto-alarm both are nouns.

Word	Noun	Adjective	Verb	Adverb
autoalarm	Yes	No	No	No
auto-alarm	Yes	No	No	No

As nouns, autoalarm and auto-alarm are synonyms defined as:

autoalarm and auto-alarm: a radio receiving device used on ships that rings an alarm bell when a distress signal is received.

autoalarm (noun)	auto-alarm (noun)
a radio receiving device used on ships that rings an alarm bell when a distress signal is received.	a radio receiving device used on ships that rings an alarm bell when a distress signal is received.